This project is an investigation of the interaction of porcine low density lipoproteins and high density lipoproteins with porcine liver cell membranes. The studies are being conducted in pig hepatocytes in primary culture, and in membranes isolated from freshly prepared hepatocytes or liver homogenates. We are examining the lipoprotein specificity of the cells and membranes, and are exploring lipoprotein sructural features responsible for binding, using inhibitors and selective modification of substrates. We will attempt to establish physiological consequences of lipoprotein binding to hepatocytes, examine the possible regulation of the binding site by lipoproteins, and attempt to purify lipoprotein-binding plasma membranes from isolated hepatocytes. The studies should provide insight into the mechanism of specific lipoprotein binding in normal liver cells and has relevance to the pathogenesis of atherosclerosis in humans.